1. Field of the Invention
The present invention relates to cardiopulmonary apparatus and methods for preserving the viability of organs in an expired organ donor for subsequent transplantation by providing extracorporeal blood oxygenation and circulation. The apparatus and methods are useful in a variety of settings including hospitals, remote areas, accident sites, and during transport, for example in an ambulance, boat, or helicopter. The apparatus and methods are useful to preserve the viability of organs in a clinically dead patient for subsequent transplantation under circumstances that presently prohibitive to donor organ preservation.
2. Description of Related Art
Perfusion of a deceased organ donor with oxygenated blood must be initiated quickly after the organ donor dies in order to preserve the viability of the organ(s) to be transplanted. Heart-lung and cardiopulmonary assist machines are known but their use in emergency, transport, and field situations is hindered, in part, by the relatively long period of time and the requirement for well trained specialists for priming the machines and safely bringing them into operation.
During machine priming, a liquid is used to fill the blood-conducting components of the heart-lung machine. The priming liquid must be vented or deaerated prior to connection with the organ donor's vascular system and initiating heart-lung machine operation in order to eliminate air bubbles, which can cause thrombosis and damage organs. Known heart-lung machines require considerable time as well as a trained perfusion specialist for priming and operation.
The apparatus and methods of the present invention overcome the aforementioned limitations of prior art heart-lung machines by providing for a compact and portable heart-lung machine that can be primed and ready for operation in less than about 10 minutes. Priming of the extracorporeal blood circuit with priming liquid and de-airing is performed with little or no human intervention. The present heart-lung machine is self-contained and has an internal power supply, and may be connected to an external power supply such as an on-board power supply of an emergency land, air, or sea transport vehicle. Furthermore, no perfusion specialist is required for set up or operation and the machine may be constructed to meet requirements for regulatory approval for transport use. The machine may for instance in particular meet requirements of the EN 1789 standard for use in humid environments, water subjection, and pass shake and crash tests involving up to 9-10 g forces.
The present invention is made possible, in part, by a number of advancements in heart-lung machine technology including a fast-closing clamp, a fast-priming extracorporeal blood oxygenation, deaeration and circulation system, and an air bubble detection system, which are described in co-assigned U.S. application Ser. No. 11/284,515 filed Nov. 22, 2005; Ser. No. 11/366,342, now U.S. Pat. No. 7,597,546 filed Mar. 2, 2006; Ser. No. 11/366,914, now U.S. Pat. No. 7,367,540 filed Mar. 2, 2006; and Ser. No. 11/544,524 filed Oct. 30, 2006, which are incorporated by reference herein in their entirety. The apparatus and methods of the invention are also made possible, in part, by a multistage air removal system and various other components and procedures described herein.